The present invention relates to a pressure relief port which regulates the pressure within an enclosure and, in particular, to a miniature pressure relief port preferably for use in regulating the pressure within commercial refrigeration enclosures.
A commercial refrigeration enclosure generally includes a sealed room with a door which can be opened and closed. Opening and closing of the door of commercial refrigeration equipment can cause a substantial and undesired change in pressure within the enclosure. Thus, where the door closes inwardly towards the enclosure, an indesirable build-up of pressure within the enclosure will be created. It is therefore necessary to provide for equalization of the pressure on opposite sides of the refrigeration enclosure while preventing random flow of air therebetween which would have an adverse effect on refrigeration.
A mere opening or vent port in the wall of such an enclosure is insufficient since there will be random flow of air therein, transfer of heat therethrough and potential frost built-up. Accordingly, there have been various proposals for vent ports which are somewhat complicated in structure and generally expensive to manufacture. One type of shielded vent port of the type under discussion is disclosed in U.S. Pat No. 4,257,445 issued on Mar. 24, 1981.
Accordingly, it is desired to provide an improved pressure relief port designed especially for use in commercial refrigeration equipment of the "reach in" type where the opening and closing of a door on the refrigeration enclosure causes a change of pressure within the enclosure.